Side-chain opening of steroidal sapogenins to form 22-oxocholestanic skeletons: An approach to analogues of the aglycone of the potent anticancer agent OSW-1

the side-chain opening of 25r and 25s steroidal sapogenins to form 22-oxocholestanic skeletons is described. the transformation was produced under mild conditions providing high yields (70-87%), in a one pot procedure (some acetylated starting material is recovered). this methodology yields 17-deoxy-26-oxy analogues of the aglycone of the potent anticancer agent osw-1. all products were fully characterized by 1d and 2d nmr; the most representative displacements are briefly discussed.